Hyperthyroidism

The term ‘hyperthyroidism’ refers to any condition in which there is too much thyroid hormone in the body or an overactive thyroid gland. It is a common disorder, affecting over 2 million Americans, most of whom are women. There are several types of hyperthyroidism, each associated with a different particular cause and different options for therapy which include:

  • Graves’ disease (also called diffuse toxic goiter) caused by antibodies in the blood, which stimulate the thyroid to grow and produce excess hormone
  • Toxic multinodular goiter, an enlarged, lumpy thyroid gland in which individual thyroid nodule(s) are responsible for excess thyroid hormone production
  • Thyroid adenoma, or a single nodule within the thyroid gland
  • Thyroiditis (inflammation of the thyroid), a self-limiting disease possibly caused by an infection and often associated early on with an increased release of thyroid hormone

Hyperthyroidism Symptoms: Thyroid hormone regulates the body’s metabolism; accordingly, excess thyroid hormone can cause the following symptoms:

  • Nervousness, irritability, anxiety
  • Increased perspiration and heat intolerance
  • Increased resting heart rate and palpitations
  • Hypertension (high blood pressure)
  • Hand tremors
  • Weight loss or alterations in appetite
  • Frequent bowel movements- although diarrhea is uncommon
  • Thin, delicate skin, irregular fingernails and fine, brittle hair growth
  • Menstrual disturbance (decreased flow and decreased cycles)
  • Impaired fertility
  • Mental disturbances
  • Sleep disturbances (including insomnia)
  • Changes in vision, eye irritation, or exophthalmos: significant protrusion of the eyes due to swelling of the tissue behind them causing elevation of the upper eye lids (with Graves’ disease)

Diagnosis: The diagnosis of hyperthyroidism is made on the basis of findings during a physical exam and confirmed by laboratory tests and complementary functional imaging of the thyroid gland (iodine-uptake scans).

  • Thyroid stimulating hormone (TSH)- the single best screening test for hyperthyroidism; most types result in a below average level
  • Levels of thyroid hormone (thyroxine, or T4; triiodothyronine, or T3)
  • Thyroid-stimulating antibodies that cause Graves’ disease
  • Radioactive iodine scan to see whether the entire thyroid gland is overactive
  • Clues that hyperthyroidism is caused by Graves’ disease
    • Presence of Graves’ eye disease
    • Myxedema
    • Enlarged thyroid or goiter
    • History of other family members with thyroid problems (hyperthyroidism or hypothyroidism)
    • Family members with other autoimmune disorders (premature gray hair, juvenile diabetes, rheumatoid arthritis, pernicious anemia due to lack of vitamin B12, or vitiligo)